Apparatus for removing remnants of powder images in electrophotographic copying machines

ABSTRACT

An electrophotographic copying machine wherein the surplus toner which remains on the photoconductive layer of the copying cylinder subsequent to transfer of powder images onto a carrier is removed by rotary brush having radially extending bristles consisting of artificial fur or the like. The bristles are deformed on contact with the photoconductive layer and propel particles of toner against a travelling toner-retaining band which is collected by a rotary takeup reel and is guided by a wall of an expendable plastic casing for the brush and takeup reel in such a way that an unsupported stretch thereof extends from a point close to the photoconductive layer to a projection of the wall which maintains the band in contact with and causes the band to deform the bristles. The casing carries a supply reel for the band and is installed in a receptacle extending radially of the copying cylinder. The open end of the receptacle can be closed by a lid which thereby causes two clutches to engage the shafts of the brush and takeup reel with the output shafts of two discrete motors.

United States Patent 1 Eppe et al.

[451 Apr. 22, 1975 APPARATUS FOR REMOVING REMNANTS OF POWDER IMAGES INELECTROPHOTOGRAPHHC COPYKNG MACHINES [76] Inventors: Rudolf Eppe,Sudstr. 5, 8021 Taufl irchen; Georg Fryda, Ganghoferstr. 52, 8 Munich 2;Ludwig Miillritter, Gogrdelerstr 20, 8025 Unterhaching; GiintherSchnall, Garchinger Str. 20, 8052 Eching; Hans-Joachim Sclnreclte,Strehlanger ll, 8 Munich 83; Josef Pfeifer, Ter-Meer-Str. 10, 8025Unterhaching; Giintlier Abb, Meginhardstr. 30, 8031 Gilching, all ofGermany [22] Filed: Dec. 5, 1973 [21] Appl. No.: 397,652

[30] Foreign Application Priority Data Sept. 16. 1972 Germany 2245575[52] US. Cl 355/15; l5/256.52 [51] Int. Cl G03g 15/00 [58] Field ofSearch l5/l.5, 256.5, 256.51,

[56] References Cited UNITED STATES PATENTS 3.099.856 8/1963 Eichorn etal. 355/15 X Primary E.\'aminerFred L. Braun Atlorney, Agent, orFirm-Michael S. Striker [5 7] ABSTRACT An electrophotographic copyingmachine wherein the surplus toner which remains on the photoconductivelayer of the copying cylinder subsequent to transfer of powder imagesonto a carrier is removed by rotary brush having radially extendingbristles consisting of artificial fur or the like. The bristles aredeformed on contact with the photoconductive layer and propel particlesof toner against a travelling toner-retaining band which is collected bya rotary takeup reel and is guided by a wall of an expendable plasticcasing for the brush and takeup reel in such a way that an unsupportedstretch thereof extends from a point close to the photoconductive layerto a projection of the wall which maintains the band in contact with andcauses the band to deform the bristles. The casing carries a supply reelfor the band and is installed in a receptacle extending radially of thecopying cylinder. The open end of the receptacle can be closed by a lidwhich thereby causes two clutches to engage the shafts of the brush andtakeup reel with the output shafts of two discrete motors.

25 Claims, 2 Drawing Figures APPARATUS FOR REMOVING REMNANTS OF POWDERIMAGES IN ELECTROPI'IOTOGRAPHIC COPYING MACHINES BACKGROUND OF THEINVENTION The present invention relates to electrophotographic copyingmachines wherein powder images containing particles of toner are formedon a photoconductive layer and are transferred onto a carrier while thelayer travels along an endless path.

It is already known to clean the photoconductive layer upon removal of apowder image in order to remove the remaining particles of toner beforethe layer receives a fresh powder image. In heretobefore known copyingmachines, the cleaning apparatus for removing remnants of tonercomprises a rotary brush having a core which is surrounded by a coatingof felt or by discrete bristles consisting of animal hairs or of hairsmade from a suitable synthetic plastic material. Certain cleaningapparatus use brushes whose bristles consist of mink or rabbit hairs. Inmany presently known copying machines, the brush is permanentlyinstalled adjacent to the path of movement of the photoconductive layerand the cleaning apparatus further comprises a vacuum cleaner whichremoves toner particles from the bristles and prevents the thus removedtoner particles from contaminating the machine. A drawback of suchcleaning apparatus is that the provision of a vacuum cleaner contributesexcessively to their initial and maintenance cost.

It is further known to replace the vacuum cleaner with a web or band oftoner-collecting material which is biased against the bristles of therotating brush by a suitable roller and serves to collect the particlesof toner which are propelled by the bristles after the bristles are freeto reassume their undeformed positions as well as to remove tonerparticles from the brush proper. Such toner-collecting bands contributeto the lower cost of the cleaning apparatus; however, the presentlyknown bands (mainly due to the manner in which they are mounted in thecopying machine) are incapable of collecting sufficient quantities oftoner and/or of properly cleaning the rotating brush so that the copyingmachine is contaminated after short periods of use and the accumulationof toner in the brush proper is excessive.

Attempts to use electrostatic cleaning apparatus have met with littlesuccess, mainly for the reasons outlined in connection with cleaningapparatus which employ vacuum cleaners.

SUMMARY OF THE INVENTION An object of the invention is to provide anelectrophotographic copying machine with a novel and improved apparatuswhich is capable of collecting large quantities of surplus toner withoutresorting to vacuum cleaners and/or electrostatic cleaning devices.

Another object of the invention is to provide novel and improved meansfor collecting toner particles which are removed from thephotoconductive layer by one or more rotary brushes.

A further object of the invention is to provide a cleaning apparatuswhich is sufficiently inexpensive to warrant the manufacture of themajority of its parts as an expendable assembly which can be discardedafter a prolonged period of use.

An additional object of the invention is to provide a novel and improvedmounting for the toner-collecting band or web in an apparatus forcollecting surplus toner in an electrophotographic copying machine.

Still another object of the invention is to provide a cleaning apparatuswherein the rotary parts are automatically disengaged from one or moreprime movers when the user decides to gain access to the cleaningapparatus.

A further object of the invention is to provide a cleaning apparatuswhich can be installed in existing copying machines with minimal andinexpensive alterations of such machines.

Another object of the invention is to provide a cleaning apparatus whosetoner-collecting capacity is surprisingly high in spite of the fact thatthe tonercollecting parts are preferably of the expendable type and thatthe apparatus does not employ electrostatic and/or vacuum-operated tonercollecting devices.

The invention is embodied in an electrophotographic copying machinewhich comprises a photoconductive layer movable in a predetermineddirection (the layer may be a cylinder which rotates about its axis) andalong an endless path to thereby receive tonercontaining powder imagesin a first portion and to be relieved of powder images in a secondportion of the path whereby at least some toner particles normallyadhere or are likely to adhere to the layer in a third portion of thepath along which successive portions of the layer travel on their wayfrom the second toward the first path portion. In accordance with afeature of the invention, the copying machine further comprises acleaning apparatus which serves to remove toner from the photoconductivelayer in the third portion of the endless path and comprises asubstantially cylindrical brush having a rotary core and flexibletoner-removing bristles which surround the core and contact successiveincrements of the layer whereby the bristles undergo a certain amount ofdeformation in response to movement into contact with the layer andreassume their undeformed positions relative to the core in response totermination of contact with the layer, a source (e.g., a supply reel) ofbank-like toner-collecting material, rotary takeup means for drawing theband-like material from the source, and guide means for the band-likematerial. The guide means may constitute a wall member which forms partof an expendable casing or magazine for the brush and takeup means andwhich comprises a projecting portion (e.g., a rib which is parallel tothe axis of the brush) for urging the band-like material against thebristles downstream of the locus where the bristles move away fromcontact with the layer and a second portion (e.g., a suitably roundeddeflector) which is closely adjacent to the layer. The band-likematerial travels from the second portion toward the projecting portionof the guide means so that a stretch of the band-like material betweenthe two portions of the guide means remains unsupported and serves tointercept toner particles which leave the brush as a result oftermination of deformation of the bristles and/or under the action ofgravity and/or centrifugal force.

The projecting portion of the guide means preferably causes theband-like material to penetrate into the brush and to deform thebristles to thereby further enhance the separation of toner particlesfrom the brush before the bristles return into contact with thephotoconductive layer.

, vantages thereof, will be best understood upon perusal of thefollowing detailed description of certain specific embodiments withreference to the accompanying drawing. I

I BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary sectionalview of an electrophotographic copying machine which embodies theimproved cleaning apparatus; and

FIG. 2 is a sectional view as seen in the direction of arrows from theline 11-11 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. 1,there is shown a portion of an electrophotographic copying machine whichcomprises a housing 1 including two mutually inclined walls v 2, 3 whichform part of a channel or receptacle fora magazine or casing 12. Thereceptacle or channel including the walls 2, 3 has an open inner endwhich is adjacent to the periphery of a rotary copying cylinder 4 havinga cylindrical layer 5 of photoconductive material. The outer end of thereceptacle or channel including the walls 2, 3 is also open but can beclosed by a cover member or lid which is pivotally secured to thehousing 1 by a hinge 6. That portion of the lid 7 which is remote fromthe hinge 6 is provided with a projection 7a which can be engaged by aretaining lever pivotally mounted in the housing 1, as at 45, and beingbiased against a stop 46 by a relatively weak helical spring 47. The lid7 is closed to assume the position which is shown in FIG. l when thecopying machine is in use and can be forcibly pivoted to an openposition (whereby the projection 7a is automatically disengaged from thelever) when the operator wishes to gain access to the cleaning apparatusor when the operator wishes to remove a used cleaning apparatus prior toin sertion of a fresh cleaning apparatus into'the channel.

.When the copying machine is in use, the copying cylinder 4 is driven torotate in the direction indicated by an arrow A whereby the layer 5travels along an endless path in a first portion of which it receives apowder image, in a second portion of. which it is relieved of the powderimage, and a third portion of which is adjacent to the inner 'endof thechannel including the walls 2 ,and3.

The exact construction of all devices at the stations which are adjacentto the'path of the layer 5 forms no part of the invention. FIG. 1 merelyshows a charging The present invention provides a novel and improvedapparatus whichcan be employed to remove from the layer 5 remnants oftoner before the cleaned portions of the layer 5 return into registerwith theopening in the light conducting shaft 11. Were the particles oftoner permitted to adhere to the layer 5, they could'influence thequality of the next powder image and/or contaminate the copying machine.

The cleaning or toner removing apparatus comprises the aforementionedmagazine or casing 12 which is preferably mass-produced of a suitablesynthetic plastic material so that it can be discarded after a certainperiod of use, together with all such components of the cleaningapparatus which are mounted therein and/or path of the layer 5. Thestation where the particles of toner are sprinkled onto the layer 5 toform thereon a thereon. The casing l2tapers in a direction toward theinner end of the receptacle or channel including the walls 2, 3 so thatit can be automatically arrested at or close to an optimum distance fromthe layer 5 on the copying cylinder 4. The side walls 12f, 123 (see HO.2)

of the casing 12 are provided with aligned openings for two stub shafts13a, 13b at the respective axial ends of a cylindrical core 13 formingpart ofa substantially cylindrical brush further having a sleevebodyconsisting of bristles or hairs 14. For example, the core 13 may have adiameter of 30 millimeters and each bristle [4 may have a length of llmillimeters. The bristles 14 may consist of flexible synthetic plasticmaterial such I as is used for the making of artificial furs and areglued I mined optimum speed, for. example, at 600-800 RPM.

The distance between the axis of the core 13' and the axis of thecopying cylinder 4 is preferably such that the minimum distance betweenthe peripheral surface of the core 13 and the layer 5 is slightly lessthan the length of a bristle 14, e.g., 9-10 millimeters.

-When the cylinder 4 is driven counterclockwise and the brush l3, 14also rotates counterclockwise, successive bristles 14 contact the layer5 at the locus M and move out of contact with the layer 5 at the locusN.

Thus, the bristles are deformed at M and are permitted to reassume theirnormal positions relative to the core 13 as soon as they move beyond thelocus N.

The side walls 12f, 12g of the casing 12 are further provided withaligned openings for stub shafts 15a, 15b at the respective axial endsof a second core 15 which forms part of or constitutes a simple takeupreel for band-like, toner-collecting material 16 (hereinafter called theband for short). The source of band 16 is a supply reel having a'core 18provided with stub shafts 18a, 18b which extend with at least somefriction into complementary openings or slots provided therefor inbearing brackets 17 which are integral with and are located externallyof the casing 12. As shown in FIG. 1, the bearing brackets 17 extendtoward the lid 7. The surfaces 17A bounding the openings or slots in thebearing brackets 17 can be said to constitute a rudimentary brakingmeans which insures that the supply reel including the core 18 offers acertain resistance to rotation when the takeup reel (core 15) is rotatedcounterclockwise, as viewed in FIG. '1, in order to collect the band 16.However, it is equally possible to provide the bearing brackets 17 withsuitable friction pads which bear against one or both stub shafts 18a,18b and/or against the core 18 to thereby offer a certain resistance toclockwise rotation of the supply reel. When the core of the takeup reelis rotated in a direction to collect the band 16, the latter advances inthe direction indicated by an arrow C. The guide means for that portionof the band 16 which extends between the supply and takeup reelsincludes a section or wall member 12a of the casing 12. The wall member12a has an external surface 12A which faces away from the brush 13, 14and an internal surface 128 which faces the adjacent bristles 14. Duringtravel from the core 18 toward the core 15, successive increments of theband 16 travel along the external surface 12A and thereupon along theinternal surface 128.

The wall member 120 has an end portion or deflector 12b which is closelyadjacent to and defines with the layer 5 a narrow gap G through whichthe band 16 passes on its way toward the core 15 of the takeup reel. Thewidth of the gap G is preferably constant, i.e., the portion 12b of thewall member 12a is preferably parallel to the axis of the cylinder 4 andhence also to the axis of the core 13. The wall member 12a furthercomprises a substantially triangular projecting portion 12c whichextends from the surface 12B and deforms the adjacent bristles 14. Thatstretch (16a) of the band 16 which extends between the portion 12b andthe projecting portion 12c is unsupported because the wall member 120 isprovided with a depression or recess 12d. The band 16 contacts thebristles 14 in a region ahead of the projecting portion 12c, asconsidered in the direction of rotation of the brush 13, 14. The widthof the gap G between the portion 12b of the wall member 12a and thelayer 5 on the copying cylinder 4 need not substantially exceed 1millimeter and is preferably between 0.5-1 millimeter. The core 15 ofthe takeup reel is driven by a second prime mover (e.g., an electricmotor 39 shown in FIG. 2) at such a speed that the lengthwisemovement ofband 16 in the direction indicated by the arrow C is very slow, e.g., lmillimeter per copy. The projecting portion 120 can penetrate into theannulus of bristles 14 to a depth of 2-3 millimeters, i.e., the distancebetween the tip of the projecting portion 12c and the periphery of thecore 13 is preferably 8-9 millimeters. The stretch 16a of the band 16 isunder tension due to the provision of aforementioned braking means onthe bearing brackets 17 for the core 18 of the supply reel.

A further wall member or portion 12e of the casing 12 defines with thelayer 5 a second gap GG which is adjacent to the locus MM. The left-handend portion of the wall member 122 is connected with an elastic sealingelement or lip 19 which contacts the layer 5 and the bristles 14 in theregion of the locus M. The angle between the left-hand surface of thelip 19 and the adjacent portion of the layer 5 is a relatively smallacute angle. For example, the lip 19 may be made ofa strip of polyesterfoil having a thickness of 0.25 millimeter. The width of the lip 19 (asconsidered in the circumferential direction of the layer 5) ispreferably such that the free lower edge of the lip contacts thebristles 14 at or immediately adjacent to the locus M. This prevents theaccumulation of toner particles in the region of the lower edge of thelip 19 because the bristles 14 sweep the toner away toward and beyondthe locus N so that the toner particles impinge on the stretch 16a ofthe band 16. The main purpose of the lip 19 is to prevent escape oftoner particles from the casing 12 along the wall member 12e; suchparticles could contaminate the corona discharge device including theelectrode 9.

The copying machine is provided with two clutches which can be engagedto respectively connect the output shafts 42, 43 of the motors 38, 39with the cores 13, 15. Furthermore, the copying machine comprises means(including the lip 7) for engaging or disengaging the two clutches. Thearrangement is preferably such that, when the casing 12 is properlyinserted into the channel or receptacle including the walls, 2, 3, amovement of the lid 7 to closed position automatically entails anengagement of the two clutches so that the motor 38 can drive the core13 and the motor 39 can drive the core 15, and that a movement of thelid 7 to open position automatically results in disengagement of the twoclutches so that the casing 12 can be withdrawn through that (outer)open end of the channel which is normally closed by lid 7. The actuatingmeans for the two clutches comprises a first rod 22 which isarticulately connected to the lid 7, as at 22a and is furtherarticulately connected to a lever 23 in the housing 1. The lever 23 iscoupled with a similar lever 25 by means of a second rod 24 (see alsoFIG. 2). The levers 23, 25 are respectively connected to and can turntwo sleeves 27, 26 which are respectively rotatable on fixed cylindricalbearing elements 41, 40. The sleeves 26, 27 are respectively providedwith suitable inclined (substantially helical) cam faces 26a, 27a whichcan cooperate with complementary cam faces 28a, 29a of two sleeves 28,29 in the housing 1. The sleeves 28, 29 are movable axially of therespective bearing elements 40, 41 and are rigidly connected to eachother by a web or rib 30 which is biased upwardly, as viewed in FIG. 2,by a helical spring 31 so that the cam faces 28a, 29a respectively bearagainst the cam faces 26a, 27a.

The bearing elements 40, 41 respectively receive axially movable clutchelements in the form of bolts 32, 33 which are respectively aligned withthe stub shafts 13a, 15a of the cores 13, 15. The bolt 32 has anenlarged portion or head 32a which is outwardly adjacent to the bearingelement 40 and sleeve 28, and the bolt 33 has a similar head 33a whichis outwardly adjacent to the bearing element 41 and and sleeve 29. Theinner end portions of the bolts 32, 33 are rounded and can entersuitable (preferably conical) sockets or recesses 13c, in the stubshafts 13a, 150 when the bolts 32, 33 are caused or allowed to movetoward the cores 13, 15. The bolts 32, 33 are respectively biased towardthe cores 13, 15 by helical springs 34 and 35 which react against thehousing 1 and respectively bear against collars 32b, 33b.

The stub shafts 13b, 15b are respectively provided with recesses orsockets 13d, 15d for conical centering projections 36, 37 of the outputshafts 42, 43. The centering projections 36, 37 cooperate with therounded inner end portions of the bolts 32, 33 to respectively maintainthe cores 13, 15 in exact parallelism with each other and with the axisof the cylinder 4 when the lid 7 is closed. The conical centeringprojections 36, 37 preferably consist or carry coats of frictiongenerating material so that they can rotate the cores 13, 15 by frictionwhen the motors 38, 39 are on.

When the lid 7 is moved to the closed position of FIG. 1, the rods 22,24 turn the sleeves 27, 26 by way tions indicated by arrow D so that therounded inner end portions of the bolts 32, 33 respectively penetrateinto the sockets 13c, 15c and cause the sockets 13d. 15d to receive theconical centering projections 36, 37.

v. The cleaning apparatus is then ready for use and begins to accumulatetoner'particles as soon asthe motors 38, 39 are started. It will benoted that the closing of the .lid 7' not only results in establishmentof a driving'connection between the output shafts 42, 43 andthe cores13, 15 but that such closing also resultsin automatic centering of thecores 13, 15 with respect to the bolts 32, 33 and projections 36, 37 andhence in a movement of the brush and takeup reel to optimum positionswith respect to the layer on the copying cylinder 4.

The inclination of the cam faces 26a, 27a, 28a, 29a is selected in sucha way that the heads 32a, 33a move away from the, sleeves 28, 29 whenthe rounded inner end portions of the bolts 32, 33 extend into thesockets 130, 150. Thus, the bolts 32, 33 are then free to per- I formlimited axial movements. This is desirable to insure that the cores 13,are properly centered in spite of eventual deviations of the dimensionsof sockets 13c, 13d, 15c, 15d from optimum dimensions and in spite ofeventual substantial clearances with which the stub which are removedfrom the layer 5 by the bristles 14 are propelled against the stretch16a of the band 16 between the portions 12b and 12c of the wall memberl2a. The material of the band 16 is such that it retains the tonerparticles and transportsthe intercepted particlestoward the core 15 ofthe takeup reel. This insures that the particles of toner cannot enterthe copying machine proper where they could contaminate the parts atvarious stations surrounding the copying cylinder 4. Thus, thecontamination of copying machine is avoided in spite of the fact thatthe cleaning apparatus does not employ a vacuum cleaner or anelectrostatic toner collecting device. Moreover, the bristles l4cooperate with the band 16 to insure a thorough and reliable cleaning ofthe layer 5 because the particles of'toner which reach the stretch 16aadhere to the band and are transported away from the layer 5. Stillfurther, the band 16 prevent a premature saturation of the brush withparticles of toner, not only because the particles whichare propelled bythe bristles 14 from the locus N toward the stretch 16a adhere to theband 16 but also because the stretch 16a contacts the bristles 14immediately upstream of the projecting portion 120 which results inremoval of substantial quantities of toner particle sfrom' the bristles14. Since the stretch 16a travels v.jna di rection away from the gap G,the band 16 effectively prevents even minor accumulations of tonerparticles in the region of this gap when the copying machine is in use.Accumulations of toner in the region of the gap G are highly undesirablebecause such toner could be entrained by the layer 5 beyond the cleaning16a, i.e., which continue to adhere to the bristles 14 while thebristles move-from the locus N toward the projecting portion 120, areseparated from the bristles 14 during'contact with the band 16 upstreamof the portion 120. The stretch 16a is in a highly satisfactory wipingcontact with the bristles which also contributes to more reliabletransfer of toner particles onto the stretch 16a before this stretchadvances beyond theregion of direct contact with the bristles. Thedeformation of the bristles l4 in response to direct contact with theyare permitted to abruptly straighten out and to propel remainingparticles of toner toward the portion 16b of the band 16, i.e., againstthe band portion between the projecting portion 12c and the takeup reel.Extended experiments with our cleaning apparatus indicate that theremoval of toner particles from the bristles 14 in the regions betweenthe locus N and the roll of convoluted band 16 on the core 15 of thetakeup reel is just as satisfactory as when the band is cleaned by avacuum generating device or by an electrostatic device. Thus, a thoroughcleaning of those bristles 14 which return into contact with the layer 5can be achieved at a cost which is but'a small fraction of the cost ofcleaning apparatus employing vacuumcleaners and/or electrostatic tonerremoving devices. The provision of a relatively simple projectingportion 12c in place of conven tional rollers or drums alsocontributesto the simplicity and lower cost of the improved cleaningapparatus. The

station to interfere with the formation of satisfactory radius ofcurvature of the tip of the projecting portion 12c is preferably verysmall (smaller than the radius of the smallest roller which is usedin'place of the projecting portion in conventional cleaning apparatus);this insures an abrupt deformation and an abrupt straightening ofbristles 14 which travel toward, past and beyond the projecting portion120. Such abrupt deformation and straightening enhance the transfer oftoner particles from the bristles 14 onto the stretch 16a and bandportion 16b.

The'recess or depression 12d in the surface 128 of the wall member 12apreferably extends all the way from the portion 12b to the portion 1200fthe wall member 120. This enables the stretch 16a to flex and to overliea substantial portion of the brush 13, 14 (FIG. 1 shows that the stretch16a contacts the bristles 14 along an arc of approximately 45). 7

The thorough and reliable cleaning action of the band 16 renders itpossible to transport the band at a.

very low speed without risking excessive accumulations of tonerparticles inthe brush 13, 14, i.e., between the bristles l4, and withoutrisking the possibility of transfer of toner particles from the band 16onto the brush. The particles which would be removed from the'band 16 bythe bristles 14 would be transferred onto the layer 5 in the region ofthe locus M. The possibility to transport the band 16 at an extremelylow speed (as mentioned above, the toner can be transported through adistance of one millemeter per print) renders it possible to constructthe casing 12 and the parts mounted therein and/or thereon as anexpendable assembly which can be discarded after a relatively longperiod of use. The open side of the casing 12 (such open side faces thelayer on the copying cylinder 4) is completely closed by the lipl9,bristles l4 and band 16 so that the particles of toner cannot escapefrom the casing 12 even if the latter is practically filled with toner.i.e., even when the major part of the band 16 is already convoluted onthe core 15 of the takeup reel. When the supply of clean band 16 on thecore 18 is exhausted, the lid 7 is moved to its open position to therebyautomatically disengage the motors 38, 39 from the cores l3, l5, and theoperator simply withdraws the casing 12 with the empty core 18 from thereceptacle including the walls 2, 3 prior to inserting a new casing witha full supply of fresh band 16 on the core 18. The lid 7 is thereuponreturned to its closed position and the copying machine is ready foruse.

The lip 19 is inclined and dimensioned in such a way that it properlyengages the layer 5 and the bristles 14 of the respective brush even ifthe dimensions of one casing 12 deviate substantially from thedimensions of the next-following or preceding casing. This is attributedto the fact that the lip 19 makes an acute angle with the adjacentportion of the layer 5 and also that the width of the lip suffices toinvariably insure the establishment of contact with the bristles 14 inthe region of the locus M where the bristles undergo deformation inresponse to movement into contact with the layer 5.

The entire casing 12 preferably consists of a suitable synthetic plasticmaterial which is sufficiently inexpensive to justify its disposaltogether with the cores 13, 15 and 18. The major parts of the twoclutches, the motors 38, 39 and the means for actuating the clutches aremounted in the housing 1 so that they can be used again and again evenif the dimensions of successively inserted casings deviate substantiallyfrom each other.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featureswhich fairly constitute essential characteristics of the generic andspecific aspects of our contribution to the art and, therefore, suchadaptations should and are intended to be comprehended within themeaning and range of equivalents of the claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims:

1. ln an electrophotographic copying machine, a combination comprising aphotoconductive layer m0vable in a predetermined direction along anendless path to thereby receive toner-containing powder images in afirst portion of said path and to be relieved of powder images in asecond portion of said path whereby at least some toner particlesnormally adhere to said layer in a third portion of said path alongwhich said layer advances toward said first portion; and apparatus forremoving toner from said layer in said third portion of said path,comprising a substantially cylindrical brush including a rotary core andflexible toner-removing bristles surrounding said core and arranged tocontact successive increments of said layer whereby said bristlesundergo deformation in response to movement into contact with said layerand reassume their undeformed positions relative to said core inresponse to termination of contact with said layer, a source ofband-like toner-collecting material, rotary takeup means for drawingsaid band-like material from said source, and guide means having aprojecting portion for urging said band-like material against saidbristles downstream of the locus where said bristles move away fromcontact with said layer and a second portion adjacent to said layer,said band-like material being arranged to travel from said secondportion of said guide means toward said projecting portion of said guidemeans so that a stretch thereof between said portions of said guidemeans intercepts toner particles which leave said brush as a result oftermination of deformation of said bristles and/or under the action ofcentrifugal force.

2. A combination as defined in claim 1, wherein said source comprises arotary supply reel for band-like material and said projecting portion ofsaid guide means is spaced apart from said locus and extends into thepath of movement of said bristles so that the bristles are flexed by theband-like material in the region of said projecting portion.

3. A combination as defined in claim 1, wherein said guide meanscomprises a wall member having a first surface facing away from saidbrush and a second surface facing said brush, said band-like materialbeing arranged to travel from said source toward said second portion ofsaid guide means along said first surface and to travel from said secondportion of said guide means toward said projecting portion of said guidemeans along said second surface of said wall member.

4. A combination as defined in claim 1, wherein a portion of saidstretch contacts said bristles in a region located ahead of saidprojecting portion, as considered in the direction of movement of saidband-like material from said second portion of said guide means towardsaid projecting portion of said guide means.

5. A combination as defined in claim 1, wherein said band-like materialis spaced apart from said guide means between said second portion ofsaid guide means and said projecting portion of said guide means so thatsaid stretch of said band-like material is unsupported.

6. A combination as defined in claim 5, wherein said guide means has arecess extending between said second portion of said guide means andsaid projecting portion thereof to provide room for the flexing of saidstretch by the bristles of said brush.

7. A combination as defined in claim 1 wherein said second portion ofsaid guide means defines with said layer a narrow gap of substantiallyconstant width through which said band-like material advances from saidsource toward said projecting portion.

8. A combination as defined in claim 7, wherein said second portion ofsaid guide means constitutes a deflector which changes the direction ofmovement of said band-like material through an obtuse angle.

9. A combination as defined in claim 7, wherein said layer is acylindrical layer and the axis of said brush is parallel to the axis ofsaid layer, said second portion of said guide means being elongated andparallel to the axis of said layer.

10. A combination as defined in claim 1, wherein said apparatus furthercomprises a casing including said guide means and having an open endadjacent to said layer in the region of said third portion of said path.

11. A combination as defined in claim 10, wherein said brush and saidtakeup means are rotatably mounted in said casing and said casingcomprises external bearing means for said source.

7 said path.

12. 'A combination as defined in claim 11, wherein said source comprisesa rotary supply j reel for said band-like material and said bearingmeans comprises means for braking said supply reel while said takeupmeans rotates to collect said band-like material so that the band-likematerial is tensioned between said supply reel and said takeup means.

13. A combination as defined in claim 10, wherein said casing includes aportion adjacent to said layer and located in the region of the locuswhere said bristles move into contact with said layer, andfurther'compris- I ing elastic sealing means provided on said portion of'said casing and engagingsaid layer.

114. A combination as defined in claim 13, wherein said sealing meanscomprises a flexible lip making an acute angle with the adjacent portionof said layer.

. 15. A combination as defined in'claim l3, wherein said sealing meanscontacts said bristles.

16. A combination as defined in claim 10, wherein said casing isexpendable and consists of synthetic thermoplastic material. i

17. A combination as defined in claim 16, wherein said casing comprisesintegral bearing means-for said source. j

18. A combination as defined in claim 10, wherein said brush and, saidtakeup means are rotatably mounted in said casing and further comprisinga receptacle for-said casing, said casing being movable in saidreceptacle toward and away'from said third portion of l9.A combinationas defined in claim 18, wherein said layer is a cylindrical layerandsaid receptacle extends substantiallyradially .of said layer.

20. A combination as defined in claim 1, further comprising wall meansfor supporting said brush and 12 said takeup means and means forcentering said brush and said takeup means in said wall means.

21. A combination as defined in claim 1, wherein said core of said brushcomprises first shaft means and said takeup means comprises second shaftmeans, and further comprising drive means for said shaft means andclutch means actuable to connect said shaft means with said drive means.

22. A combination as defined in claim 21, further comprising areceptacle for said brush and said takeup means, said receptacle havingan open end and further comprising means for actuating said clutch meansincluding cover means for the open end of said receptacle. said covermeans being movable between open and closed positions to therebyrespectively disengage and engage said clutch means.

23. A combination as defined in claim 22, wherein said clutch meanscomprises reciprocable first and sec- 0nd clutch elements which arerespectively coaxial ment relative to said motion transmitting means.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO..3,879,l24

DATED Apr. 22, 1975 INVI'NtORth) ;Rudolf Eppe, Georg Fryda, LudwigM'illritter, Gunther Schrtall,

Pans-Joachim Schrecke, Josef Pfeifer and Gunther Abbe It is certlftedthat error appears III the above-Identified patent and that smtt LettersPatent arr: hereby corrected as shown below;

In the heading on the cover sheet insert the name and address of theassignee as follows:

- Agfa-Gevaert Aktiengesellschaft, Leverkusen, Germany Signed and Scaledthis A ties I:

RUTH C. MASON C. MARSHALL DANN ('mnmm'inncr uj' Iurcn/s um/ 'lrutlcmurkx.4 Hosting ()jft'cer UNITED STATES PATENT OFFICE CERTE'FICAIE 0FCORRECTION PATEN'I NO. 13,879,124

DATED Apr. 22, 1975 mvr'NroRrs) .Rudolf Eppe, Georg Fryda, Ludwig Mlillritter, Gx'inther Schnall,

Hans-Joachim Schrecke, Josef Pfeifer and Gr inther Abbe H 15 C(Zfllflfldthat error appears III the nb0ve--1dent|flr:d patent and that smrlLetters Patent arr: hereby correcleri as shown below:

In the heading on the cover sheet insert the name and address of theassignee as follows:

Agfa-Gevaert Aktiengesellschaft, Leverkusen, Germany gigned and gealcdthis RUTH C. MASON .4 resting ()fj'rver C. MARSHALL DANN('11I)1rr1r.s.rimrcr nj'lulcnls uml 'l'rurlvmurkr

1. In an electrophotographic copying machine, a combination comprising aphotoconductive layer movable in a predetermined direction along anendless path to thereby receive toner-containing powder images in afirst portion of said path and to be relieved of powder images in asecond portion of said path whereby at least some toner particlesnormally adhere to said layer in a third portion of said path alongwhich said layer advances toward said first portion; and apparatus forremoving toner from said layer in said third portion of said path,comprising a substantially cylindrical brush including a rotary core andflexible toner-removing bristles surrounding said core and arranged tocontact successive increments of said layer whereby said bristlesundergo deformation in response to movement into contact with said layerand reassume their undeformed positions relative to said core inresponse to termination of contact with said layer, a source ofband-like toner-collecting material, rotary takeup means for drawingsaid band-like material from said source, and guide means having aprojecting portion for urging said band-like material against saidbristles downstream of the locus where said bristles move away fromcontact with said layer and a second portion adjacent to said layer,said band-like material being arranged to travel from said secondportion of said guide means toward said projecting portion of said guidemeans so that a stretch thereof between said portions of said guidemeans intercepts toner particles which leave said brush as a result oftermination of deformation of said bristles and/or under the action ofcentrifugal force.
 1. In an electrophotographic copying machine, acombination comprising a photoconductive layer movable in apredetermined direction along an endless path to thereby receivetonercontaining powder images in a first portion of said path and to berelieved of powder images in a second portion of said path whereby atleast some toner particles normally adhere to said layer in a thirdportion of said path along which said layer advances toward said firstportion; and apparatus for removing toner from said layer in said thirdportion of said path, comprising a substantially cylindrical brushincluding a rotary core and flexible toner-removing bristles surroundingsaid core and arranged to contact successive increments of said layerwhereby said bristles undergo deformation in response to movement intocontact with said layer and reassume their undeformed positions relativeto said core in response to termination of contact with said layer, asource of band-like toner-collecting material, rotary takeup means fordrawing said band-like material from said source, and guide means havinga projecting portion for urging said band-like material against saidbristles downstream of the locus where said bristles move away fromcontact with said layer and a second portion adjacent to said layer,said band-like material being arranged to travel from said secondportion of said guide means toward said projecting portion of said guidemeans so that a stretch thereof between said portions of said guidemeans intercepts toner particles which leave said brush as a result oftermination of deformation of said bristles and/or under the action ofcentrifugal force.
 2. A combination as defined in claim 1, wherein saidsource comprises a rotary supply reel for band-like material and saidprojecting portion of said guide means is spaced apart from said locusand extends into the path of movement of said bristles so that thebristles are flexed by the band-like material in the region of saidprojecting portion.
 3. A combination as defined in claim 1, wherein saidguide means comprises a wall member having a first surface facing awayfrom said brush and a second surface facing said brush, said band-likematerial being arranged to travel from said source toward said secondportion of said guide means along said first surface and to travel fromsaid second portion of said guide means toward said projecting portionof said guide means along said second surface of said wall member.
 4. Acombination as defined in claim 1, wherein a portion of said stretchcontacts said bristles in a region located ahead of said projectingportion, as considered in the direction of movement of said band-likematerial from said secOnd portion of said guide means toward saidprojecting portion of said guide means.
 5. A combination as defined inclaim 1, wherein said band-like material is spaced apart from said guidemeans between said second portion of said guide means and saidprojecting portion of said guide means so that said stretch of saidband-like material is unsupported.
 6. A combination as defined in claim5, wherein said guide means has a recess extending between said secondportion of said guide means and said projecting portion thereof toprovide room for the flexing of said stretch by the bristles of saidbrush.
 7. A combination as defined in claim 1 wherein said secondportion of said guide means defines with said layer a narrow gap ofsubstantially constant width through which said band-like materialadvances from said source toward said projecting portion.
 8. Acombination as defined in claim 7, wherein said second portion of saidguide means constitutes a deflector which changes the direction ofmovement of said band-like material through an obtuse angle.
 9. Acombination as defined in claim 7, wherein said layer is a cylindricallayer and the axis of said brush is parallel to the axis of said layer,said second portion of said guide means being elongated and parallel tothe axis of said layer.
 10. A combination as defined in claim 1, whereinsaid apparatus further comprises a casing including said guide means andhaving an open end adjacent to said layer in the region of said thirdportion of said path.
 11. A combination as defined in claim 10, whereinsaid brush and said takeup means are rotatably mounted in said casingand said casing comprises external bearing means for said source.
 12. Acombination as defined in claim 11, wherein said source comprises arotary supply reel for said band-like material and said bearing meanscomprises means for braking said supply reel while said takeup meansrotates to collect said band-like material so that the band-likematerial is tensioned between said supply reel and said takeup means.13. A combination as defined in claim 10, wherein said casing includes aportion adjacent to said layer and located in the region of the locuswhere said bristles move into contact with said layer, and furthercomprising elastic sealing means provided on said portion of said casingand engaging said layer.
 14. A combination as defined in claim 13,wherein said sealing means comprises a flexible lip making an acuteangle with the adjacent portion of said layer.
 15. A combination asdefined in claim 13, wherein said sealing means contacts said bristles.16. A combination as defined in claim 10, wherein said casing isexpendable and consists of synthetic thermoplastic material.
 17. Acombination as defined in claim 16, wherein said casing comprisesintegral bearing means for said source.
 18. A combination as defined inclaim 10, wherein said brush and said takeup means are rotatably mountedin said casing and further comprising a receptacle for said casing, saidcasing being movable in said receptacle toward and away from said thirdportion of said path.
 19. A combination as defined in claim 18, whereinsaid layer is a cylindrical layer and said receptacle extendssubstantially radially of said layer.
 20. A combination as defined inclaim 1, further comprising wall means for supporting said brush andsaid takeup means and means for centering said brush and said takeupmeans in said wall means.
 21. A combination as defined in claim 1,wherein said core of said brush comprises first shaft means and saidtakeup means comprises second shaft means, and further comprising drivemeans for said shaft means and clutch means actuable to connect saidshaft means with said drive means.
 22. A combination as defined in claim21, further comprising a receptacle for said brush and said takeupmeans, said receptacle having an open end and further comprising meansfor actuating said clutcH means including cover means for the open endof said receptacle, said cover means being movable between open andclosed positions to thereby respectively disengage and engage saidclutch means.
 23. A combination as defined in claim 22, wherein saidclutch means comprises reciprocable first and second clutch elementswhich are respectively coaxial with the shaft means of said core andsaid take-up means, said actuating means further comprising motiontransmitting means for effecting the movement of said clutch elementsinto engagement with the respective shaft means in response to movementof said cover means to said closed position.
 24. A combination asdefined in claim 23, wherein said shaft means are provided with socketsfor the respective clutch elements and further comprising means forbiasing said clutch elements against the respective shaft means.